By YOUCANIC on May 23, 2019
In this guide, you will learn about problems that cause Mercedes-Benz issues and how to use Foxwell NT510 for Benz to diagnose Mercedes cluster problems yourself.
It is not uncommon for Mercedes-Benz instrument cluster (IC) to stop working, or gauges to malfunction.
Symptoms Mercedes-Benz owners may experience.
The instrument cluster itself may fail. In such cases, the cluster needs to be replaced or repaired by a professional. Mercedes-Benz dealers generally do not repair defective cluster, they only replace them. Finding an independent repair shop that specializes in instrument clusters can save you money.
When you install a new cluster, you need to use a scanner to read and transfer coding to the new cluster. This includes transfer mileage, drive authorization, user settings, etc. This must be performed with a professional scanner such as the Mercedes-Benz Star Diagnostic scanner.
You can, but the mileage will not show on the instrument cluster. It will display as ------. Used instrument cluster mileage is challenging to program.
The EEPROM memory needs to be erased before the milage can be corrected. Exceptionally few repair shops will be able to rest the mileage and program a used Mercedes-Benz cluster.
Picture of a good instrument cluster fuse.
If nothing on your instrument cluster works, the problem could be a blown fuse. If the instrument cluster doesn't turn on, it doesn't light up and none of the gauges works, check the instrument cluster fuse typically in the fuse box located on the side of the dashboard.
If the instrument cluster fuse blows it is an indication of a problem in the instrument cluster or damaged wire harness.
Low battery voltage can cause instrument cluster problems. The first indication is a warning message stating: "Battery protection, comfort functions temporarily switched off."
This issue is often caused due to a partially discharged battery.
Having to jump-start the car may cause the instrument cluster to malfunction or flicker as well.
If your gauges work erratically or seem to jump the problem could be a lousy voltage regulator.
Fully charge the battery or replace it if needed for the instrument cluster to operate normally. Some Mercedes-Benz S, E, ML, GLS models have two batteries. The main battery (G1) and a secondary auxiliary battery (G1/7). Both need to be tested and fully charged.
Jump starting the car incorrectly can cause permanent damage to the instrument cluster.
Check the ground (negative) connection at the battery terminal.
While less likely the problem, a short in the wiring harness or loose ground connection to the instrument cluster can prevent the instrument cluster from turning on. This may be the case especially if you are experiencing intermittent cluster problems.
The terminals where the wire harness plugs into the instrument cluster may develop corrosion. Remove the cluster and check. Inspect both the terminals on the instrument cluster but also the connector.
If corrosion is present, cleaning the connections can bring the instrument cluster back to life.
If your instrument cluster background lights don't turn on or is too dim the headlight switch may be defective. Try setting the headlight switch to AUTO or ON to see if any of these two settings work.
Also, remember to turn up the instrument cluster brightness.
If only one of the gauges does not work, the problem may not be the instrument cluster at all.
For example, if the fuel gauge does not work or intermittently works, the problem typically is with the fuel level sending unit installed in the trunk instead of the instrument cluster.
If you have more than one gauge not working, the problem may be a defective SAM unit.
There are several tests that you can carry to check Mercedes-Benz operation.
Test you can perform:
To carry out proper diagnostics you will need an OBD2 scanner that is capable of diagnosing Mercedes-Benz instrument cluster module.
Scanners that you can use: